Happy International Water Day!
22 March 2026
Every summer, coastal towns around the Baltic Sea welcome thousands of visitors. While tourism brings important economic benefits, it also places heavy seasonal pressure on local wastewater systems – many of which were originally designed for much smaller winter populations.
This challenge is especially significant for small wastewater treatment plants serving fewer than 2000 population equivalents (PE). During peak tourist season, these facilities can be pushed beyond their intended capacity, increasing the risk of nutrient discharge and contributing to eutrophication in sensitive coastal waters.
Our NURSECOAST-II project is addressing this issue by piloting innovative and flexible solutions. Recognising that there is no single universal approach to wastewater treatment, the project applies a 5R framework for sustainable water management:
Reduce -> Recycle -> Reuse -> Restore -> Recover
Among the solutions being tested are:
- Nanobubble aeration, which enhances oxygen transfer and provides additional treatment capacity during high-load periods
- Constructed wetlands, a nature-based solution where plants and microorganisms help filter excess nutrients and pollutants from treated wastewater
Watch our short animation below to see how these solutions work and why adapting wastewater systems to seasonal tourism is essential for protecting the Baltic Sea and ensuring cleaner, healthier coastal environments for both residents and visitors.


